الفهرس 
Incidence And Epidemiology Of POAGOnly 14 pages are availabe for public view
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Abstract
Primary open angle glaucoma (POAG) is a leading cause of irreversible world blindness. The onset is without symptoms and progression occurs silently until the advanced stages of the disease, when it affects central vision. The blindness caused by POAG is irreversible .
Glaucoma suspects are defined as individuals with intraocular pressure (IOP) repeatedly above 21 mm Hg and/or appearance of the optic disc and/or nerve fiber layer that is indicative of glaucomatous optic nerve damage, but with normal visual fields.
CCT is a very important factor in managing glaucoma patients. It is necessary to adjust IOP to achieve a more accurate IOP and it allows monitoring for the risk of progression to be more precise. Any decision in glaucoma, in the absence of CCT is an uninformed one.
For more than a century, visual field evaluation has been an integral part of the diagnosis and management of glaucoma. Visual field (VF) deficits are thought to be the functional expression of ganglion cell losses.
Compared with standard perimetry, short-wavelength automated perimetry (SWAP) has been proven by studies to improve the detection of early glaucoma. However its value is limited to cases of early glaucomatous changes.
Optical coherence tomography (OCT), first described in 1991 by Huang et al, is a noninvasive, noncontact transpupillary imaging technique. It provides high-resolution images that allows in vivo measurements of the retinal nerve fiber layer (RNFL) in cross section. The third-generation instrument is able to quantify the thickness of the RNFL at a resolution of approximately eight to ten micrometer.
Significant differences in the RNFL measurements have been reported between ocular hypertensive and glaucomatous eyes compared to normal eyes.
The aim in our study was to compare the ability of OCT versus visual field in detecting and monitoring both glaucoma suspects and glaucomatous patients.
Our study was divided into two groups :
Group I: Glaucoma suspects (comparison between OCT and SWAP) and Group II: Diagnosed POAG (comparison between OCT and SAP). Follow up period was six months in all patients.
In both groups, OCT was able to detect more progression compared to visual field. In addition, it was earlier in detecting progression compared to visual field. OCT proved the ability to detect any structural changes before corresponding functional defects can be detected.
On the other hand, SWAP didn’t prove to have the same efficacy in detecting more progression in glaucoma suspects compared to OCT.
The ability of OCT to detect glaucoma suspects at risk of progression is excellent. The best parameter is the presence of ≥one quadrant abnormal at the ≤5% level. However, further studies should be carried out to evaluate the role of preserved humps detected by OCT as a parameter for glaucoma progression.
Thinner RNFL thickness measurements by OCT was clearly obvious in POAG group compared to glaucoma suspects group, again confirming the ability of OCT to detect structural changes in glaucoma and to differentiate between normal, suspects and glaucomatous.
OCT proved to be a very important and superior tool of investigation in glaucoma suspects, however in patients with established glaucoma, both OCT and SAP are considered very important tools in monitoring the disease.
With an earlier accurate diagnosis and timely therapy, the goal for this century should be to prevent glaucoma-related blindness. The goal of identifying and treating patients who are glaucoma suspect and detecting progression in glaucomatous patients is to preserve visual function by monitoring them for the earliest signs of glaucomatous damage. This will have the advantage of withholding the treatment from those who may never need it.